1. Field of the Invention
The present invention relates to a grinder that rotates and drives a disk-shaped grindstone by a motor.
2. Description of the Related Art
A grinder is capable of grinding a material to be ground by a disk-shaped grindstone that is mounted to a spindle to which the rotation of an output shaft of a motor is transmitted through a rotation transmission mechanism that uses bevel gears or the like. The spindle is forward of a housing that accommodates the motor and projected perpendicular to the output shaft.
When a metal material is ground by this type of grinder, iron powder and the like generated from such grinding is suctioned into the housing along with air for cooling the motor. If the iron powder and the like accumulate in plug/socket type terminals (e.g., accumulate between a motor terminal and a switch terminal) that connect a pair of internal electronic components, there is a risk of an electrical leak or short circuit.
Therefore, electronic components may be connected through lead wiring without depending on plugs and sockets in order to prevent electrical leaks and the like. However, this requires more time for assembly and also increases costs.
Hence, as illustrated in Japanese Patent Application Publication No. JP-2009-154271A, the applicant for the present application provides an invention in which a housing includes a motor terminal that is disposed on a stator of a motor; and a hollow cylindrical member that is fitted from an opposing direction with a switch terminal disposed on a switch block that includes a switch, whereby a plug/socket type of connection is performed inside the cylindrical member to obtain dust resistance of a terminal connection portion.
A grinder uses a controller that is an electronic component to achieve shifting, braking, and other functions. Because there are cases in which the controller is assembled to a switch block at a rear portion of the housing, there should be dust resistance between the terminals of the controller and the switch block. However, the invention of JP-2009-154271A requires interposing the cylindrical member between two electronic components, as well as the formation of an insertion portion that is inserted into the cylindrical member and holds the terminals. Therefore, the invention is difficult to employ between a switch block and a controller assembled in a narrow space at the housing rear portion.